Robust Sliding Mode Control of Nonlinear Ship Autopilot System

Designing of ship autopilot is a challenging problem because of high nonlinearity of ship dynamics and various acting disturbances. The goal of this research work is to design a robust and efficient sliding mode control for ship autopilot system. The main contribution is to employ a nonlinear dynamic model bound of uncertainties for controller design. In order to reduce the side effects of chattering phenomenon, integral switching variable is used to modify the proposed control technique. Simulation results in the rough wave condition show that the proposed sliding mode control method is able to cope with nonlinearity, uncertainty, and disturbances in the system. Moreover, the controller significantly reduces the chattering in comparison with a previous similar research.